Name
s390_pci_mmio_write, s390_pci_mmio_read - transfer data to/from PCI MMIO memory pageLibrary
Standard C library ( libc ", " -lc )Synopsis
"#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */"#include <unistd.h> int syscall(SYS_s390_pci_mmio_write, unsigned long mmio_addr ,
const void " user_buffer [. length ], \
size_t " length ); int syscall(SYS_s390_pci_mmio_read, unsigned long mmio_addr ,
void " user_buffer [. length "], size_t length );
Note :
glibc provides no wrappers for these system calls, necessitating the use of syscall(2).
Description
The s390_pci_mmio_write() system call writes length bytes of data from the user-space buffer user_buffer to the PCI MMIO memory location specified bymmio_addr
. The s390_pci_mmio_read() system call reads length bytes of data from the PCI MMIO memory location specified by mmio_addr to the user-space buffer user_buffer
. These system calls must be used instead of the simple assignment or data-transfer operations that are used to access the PCI MMIO memory areas mapped to user space on the Linux System z platform. The address specified by mmio_addr must belong to a PCI MMIO memory page mapping in the caller's address space, and the data being written or read must not cross a page boundary. The length value cannot be greater than the system page size.
Return Value
On success, s390_pci_mmio_write() and s390_pci_mmio_read() return 0. On failure, -1 is returned and errno is set to indicate the error.Errors
EFAULT The address in mmio_addr is invalid.
EFAULT user_buffer does not point to a valid location in the caller's address space.
EINVAL Invalid length argument.
ENODEV PCI support is not enabled.
ENOMEM Insufficient memory.
Standards
Linux on s390.History
Linux 3.19. System z EC12.See Also
- syscall(2)